Hello,
Like many replies I've made here over the years this has turned into a fairly long dissertation, reason being that I find it hard to provide decent amount of detail in a few short sentences. I'm told that todays audience has a much shorter attention span that that which existed before the digital age, that didn't stop me.............
I have an answer for you but must tread carefully so not to impugn the many people who learned with and use short head Spey lines. Each type of line that one can use with a 2 hand fly rod have their virtues and weaknesses, they final choice in head / belly length is up to the individual angler.
You are correct in that learning to Spey cast with a 55' line can be more difficult than with one much shorter. However, this is where we first encounter some of those virtues and weaknesses.
First it may help if I disclose to you my own learning process and the lines involved. I'll try to clarify what I mean based on my own experiences. During the mid 1990's I learned to Spey cast using a nine foot single hand rod with a standard WF #5 line. I had no idea that the casting I was doing had a name let alone that there was a river called The Spey or rods bearing the same name, I simply developed a casting style which allowed me to fish in difficult places and used it. When I bought a 13' rod I had no clue of what line to get and this was when I became first exposed to the huge array of head lengths and types of lines available for Spey casting. My first line was a Scientific Anglers 55' full Spey line with multiple tips which could be interchanged. I was not happy with that line so I bought an Ian Gordon 140 foot line which had a seventy foot head and it was with that line that I commenced to learn to cast. The process was not easy but in retrospect learning to be a good single hand caster was not a simple process either, it took a commitment to learn all the basics and then years of on the water experience to hone my skills to the point where fly fishing was not something difficult but something that I became better at every time I had a rod in my hands. Spey casting and fishing the long rods followed the same course. What I can tell you in complete honesty is that if a person learns to cast using Mid Belly lines (45 - 65' in length) that caster should be able to quickly adapt to and cast any rod and line combination using the basic Spey style casts. The same may not be true for those who learn with and then use only short head lines. Does this make the long belly caster a better caster or fisherman? That I cannot answer in a concise statement. What I can tell you is that I have been handed rods varying in length from 10'6" switch models up to 16 foot tournament rods loaded with 90 foot long belly line and have been able to cast them all with decent results. My contention would be that people who learn using longer heads can develop a better understanding of the basic mechanics of casting and what the relationship between rod power, timing, belly length and your personal control regarding how much speed and force you impart into each cast.
Now to those virtues and weaknesses ........... Short head lines rigged to a very thin running / shooting line put all of the mass needed to load a rod right in front of the user, usually with between 22 and 28 feet of line. Considering that most Spey rods are at least 12 foot long this length of fly line belly is not exactly a difficult amount of line to learn to control. Most people quickly learn to get the heads to load up a rod and are making casts quickly. There are a lot of pieces of terminology you will encounter as a beginner, things like Anchor, Anchor Point, Sweep, D Loop, Rotation, and Stance to name a few. There are others that pop up as you experience difficulties, things like; Blown Anchor, Stuck Anchor, A Tight Casting Box or Open Casting Box this box business refers to keeping the elbows and forearms tucked close to the body and is something referred to most often with the use of short head lines.
So, a very big virtue of the short head is that it can get a person casting and casting relatively well in a short period of time. It also is true that these lines are suitable for a wide range of fishing situations and are very popular. What if any then are the weaknesses of short head systems? Due to the fact that the weighted and high floating portion of the line is only 22 - 28 feet long and is connected to a very light and thin shooting line to allow for distance casting the angler has virtually no control over the head and thus the fly when a cast exceeding 45 foot or more is made. The line head and the fly are out there and that's that. There are times, situations where and when it may be desirable for an angler to be able to exert some level of control over the drifting line as well as the fly. When using a short belly line this "level of control over the drifting line" is often sacrificed. Another facet of the short head line is that while it does do a splendid job of loading up a rod and it will enable even a person new to Spey casting to achieve distance in their casts, that head must be fully recovered prior to making a second cast. Recovered by hand stripping in all of the shooting line that has exited the rod tip on each successive cast that is. One must bring the rear portion of the head (in most cases) back to and into the rod tip to some degree prior to making each cast. If and when the angler is working the fly along a current seam some 60 to 70 feet away this business of recovering the shooting line can result is a lot of hand stripping during the course of a day.
Rather than try to develop a long list of short head weaknesses, based on personal preferences I'll leave it at just two; the lack of ability to actually control the line to any great extent and a great deal of hand stripping to recover shooting lines. Do remember the virtue that these lines allow for a fast track to casting and that they will cover a wide range of fishing situations please.
When fishing longer heads of the 45 - 55 foot variety I believe that the angler can not only fish a wide range of situations but nearly all. Once the angler understands the basic mechanics and relationships mentioned earlier, those of;
"what the relationship between rod power, timing, belly length and your personal control regarding how much speed and force you impart into each cast."
In the virtue department it could be said that the longer heads allow for better control of the line and subsequently the course the fly will take in any given situation. Is this always necessary? Obviously not but I would suggest that it is a nice thing to have available when fishing. Now why did I quote the line which ended the prior paragraph? I'll give you a moment to look back at that before continuing
Once a caster has a good understanding of mechanics it is very helpful in understanding that the casts which are made with a longer head line are in fact the same casts made by your fellows using the short head lines. The Snap T,, Single and Double Spey, CackHand Casts, all are executed in the same way albeit with a longer portion of line protruding from ones rod tip. This business of "a longer portion of line protruding from the rod tip" can and does amount to a virtue of longer head lines. When I fish with a 45' Super Scandi line that line is fused to a vinyl coated running line, a line which floats and to some degree allows for mending and thus control of the rear portion of the floating head. Remember that this particular head is 45 foot long, so if the leader is 13 feet long, once we allow for the length of the extended Spey rod an angler can fish very effectively at 68 to seventy feet of distance with virtually no running / shooting line extended onto the water. At the end of each successive cast and swing there is about eight to ten foot of running line to recover prior to executing the next cast. And that next cast is as I said in all manner the same cast executed by our friends using a much shorter head length, just with a lot less stripping of line.
That casting "box", the stance and posture used when you set up and execute each cast? The box really isn't there. Due to the length of line extending from the rod tip the angler can use a more open casting style, one I like to think is more relaxed and less hurried than when casting with shorter heads. Yes there may still be 'Blown or Stuck Anchors' but I find this phenomena to be more related to varying current speeds where I may be positioned and casting from than whether or not I am either tucked in or more relaxed during the actual casting. Simple adjustments in timing generally correct any anchoring issues in my case.
This business of less stripping to recover shooting line can come into play in a big way when fishing in cold conditions. Less stripping = less water in the line guides, less water on the hand and fingers while allowing the angler to fish at a distance between 60 and seventy feet with great line and fly control ability. I personally like this aspect of a longer line and a 55 foot is even better as it extends the available range while affording the same virtue.
If there is a weakness to be associated with lines having a belly between 45 and 65 feet that weakness may be that they are a little more difficult to learn with. Once again the choice comes down to each angler wishing to learn. Are you in a hurry and demanding of results or do you want to do this for other reasons, reasons that may vary greatly between us all.
I'll close off this manifesto saying that I can fish fairly well using short head lines. They can excel when used in combination with sink tips at gaining depth. However they leave me standing there holding the cork hoping that a fish will grab the fly. The longer lines having an integrated running line fused into the line head eliminates the need for additional connections and seems more manageable to me than the thin shooting lines I've experienced with short heads.
I am not a casting expert nor do I have any vested interest in long line sales, I simply have developed a preference for the longer heads. They allow me to be interactive with my fishing efforts. Interactive in that I can mend and guide flies to my imaginary targets some of which aren't just imagination. By learning in what may be considered 'The Hard Way' I believe I've become a better caster and have successfully taught others to cast using the longer heads. Is one better than the other, short vs. long? I don't think so although each type does seem to have virtues and weaknesses
I apologize for any typo's and will take a look at this once it posts and make any edits which seem needed.
Ard
[Note] I forgot to address the question of should you get rid of the line that came with your rod? I wouldn't do that just yet.